Document
, NASA Technical Memorandum 8 1 2 1 8
i -
\
i An Investigationof a Stoppable
Helicopter Rotor With Circulation
Control
I J o hn D . B a llard, J o hn L. McCI o ud, I I I,
f and T. J . F o rsy t h
{ NASA - ' I,_I-8 1 -_ 1 d ) A_ IN V ES_IG_IION OF A ,_8Z- 1 0030 5 ' £ U PPA_L_ _IELI CC PTE_ _G_. u & _iZ_ CIR C O L A_IO_ i CON'J.'_CI. {NASA ) 372 p IIC A] _ I H E AOl CSCL O]C _ Uuc las G J / 05 2 77 3 . _ August 1980 N a tio na l Aer o na ul0cs a nd , Space Ad minis trat i on NASA Technical Memor l ndum 81218 ' i ira roB, i_
An Investigationof a Stoppable 1
Helicopter Rotor With Circulation _!
Co n trol
, , _ John D. Ballard i John L. McCIoud, III i T . J . Forsyth, NASA Ames Research C e nter , Moffett Field , California i
I
i.
t l Naliorml Aeronautics and 1 Sl _ e c e Administration I Moff e N Fi e ld.Californm 94035 AN INVE STIG A T I O N OF A STOPPABL E H ELICOPT E R R OTO R W IT H C IR CULAT I O N CO N TRO L t Jo hn D . B a llar d , Jo h n L. M cC l o ud, Ill, a n d T . J . Fo rs yt h A m es Rese a rch Ce n ter SUM M ARY A s to p pa b l e he li c op ter ro t o r with c i rcu l a ti o n co ntrol w a s in vest i ga t e d in th e Am e s 40- b y 8 0-Foot Wind Tun ne l. T h e model was te s ted a s a rotating wing, a f i x e d w in g , a nd du ri ng t ran s itio n s ta r t / s top s e qu e nce s . The o bje c t ives w e r e to d ete rmin e th e capabi l it y of t he m o d e l' s c o n trol system to ma i n ta in pitch - and rol l- moment balan ce du r ing t he s tart / s to p s e q u e nc e , t o ass e ss t he a b ilit y o f t h e bl ades to w it hs t an d t he star t / s to p l o ad s, t o de t er m ine t he a d equacy o f t he con t r ol s y s t e m to ma i nt ain b a l ance in t he he l ico pt er m o de, and to assess t he c o n trol sys tem ca p abil iti es in th e flxed-wln g mod e. This r e port p r esents t l me -hls to r y d a t a of seve r a l s t a rt / s top sequenc e s o f t he X-wing ro t o r, and t he s t eady-s t a t e da t a re l ati ng to t he mo de l as b o t h a rotor and as a fixed-wln g ai r cr a ft. I n a d d ition, s tabilit y d a ta are p res e n t ed wh ich w ere a cq u ired du ring , o pe n - l oop an d closed-loop te s t s of th e hu b moment fee db a ck c ontrol sy s t e m. !
i l INTR O D UCT ION I The ma x imum forward speed and l i ft i ng c a p abi lity of a h e l ic opter i n f or- ward flight c an be l i m i ted by retr ea ting blade stall. Tr a d i tionall y , the solu- t i on to th i s pro b lem h as been to add mor e b l a de a r e a, to employ a separat e wing, or to u s e a s e c ond contr a rot a t i ng rotor. Without exce ption the s e a pproach es have not been compl e tely s u cc e ss ful and add i tion a l l i mit i ng problems i h av e e ns u ed. T o a v oid t his prob le m, t he X- W i n g ai rc ra f t w as de ve lop e d to s top b t h e ro t or in a pr eset or ie nta t ion an d t o a l l o w th e ai r c raf t to ach i e v e hi ghe r i fo r w a rd flig ht s p eeds , w it h its we i gh t su pp o r ted b y t h e s to pped rotor a nd w ith l prop u l s ion supp li e d b y o t he r su ita ble m e a n s . This re qui r es a r o tor c onsi der- I a bl y s t if f e r t han t h o se e mploy ed b y conven ti o n al helic o p t e r s , w i th ai rfoi ls e ff ic ie nt i n bo th f o rw ard an d r ev e r se f lo w. The yaw an gl e was mai n t a i ned at 0 ° thro u gho u t t he t es t p r og r a m.
TE S T M O D U L E The t es t mo du l e i ncor po r a ted a fai red body whose p u rpo s e wa s t o s i mul at e a fusela ge, to pr o vld s a s u pport p l atf o r m f o r and t o house t he r o to r dr i ve : syste m s and th e h i gh p ressure air sys t e m . The r o to r dr i ve sys t e m co n s i sted o f a I0 0 hp va r iabl e speed m o to r an d tr a ns mi ss io n. The m o du le w a s des i g n ed t o h av e t w o m otor-co mp r e ss o r u n it s h ou sed i n t h e fa i r e d body ; h o we v e r, fo r t he t es t s rep o r t ed h ere i n , the h i g h-pre ss u re ai r sys t e m wa s lo c a ted un d er th e tunne l t est-s e c ti o n fl o or ing, and du c tin g w as pr o v i de d a l ongs i de o ne o f t h e tw o la ter al support struts (f i g. 1). An ov er flo w du m p v a lv e , d own stre am, wit h : respec t t o t he c i rcul atio n con tr ol a ir p at h, o f t h e t w o m o t o r -co m p r e sso r ! u n it s , w a s used a s a sa fe t y and air f lo w c o n t rol val ve . An airf l o w me as u rin g !
! v en turl m e t e r was d o wn str e am o f t he d um p v alv e , a nd t he a i r w as t h en duc t e d u p _ ' t o a plenum c hamb e r l o c at ed J u st b e low t he h u b .
i T h e h u b c o n t ai n e d pn eu m a ti c valve s to p e rmit co nt r ol o f t he ai rfl ow to th e bl a d e s in a co ll ecti v e m a n ner an d i n a b asic al l y cyc li c IP ( on ce p er r evo- l u t i o n) manner. Add itio na l ca p a b i l i ty o f 2 P blo w in g as we ll as m e an s f or l e adi ng- a n d / or t ra ili ng- e d g e blo win g w a s p ro vid e d. Th e bla de c on nect io n to the hub al s o allo w ed f or me c h a n ic al c ol l e c tiv e pi t c h c h a n ge .
i
RO T OR BLAD E S Fi g ure 2 sho ws a typical X-Wi ng b l ad e c ro ss s e c t i on. A i rf l o w w as po s sible from bo t h leading edges and trail in g edges alo n g the e n t ire b la d e span. The t raillng-edge j et n ozzle c on t inue d aro u n d the bla d e tip to approximately t he mld c h o rd poin t . The nozzle sl ot wi d t h was ad j u st able along the le a ding a nd trail in g edges. A i rflow o u t the no z zles provide d the circ u la t ion c on t rol. As the airflow increased by inc reasi n g t he air p ress u re in the d u c t , the j et was defle c ted b y the Coan d a effe c t to i nc rease the blade llft wi t hou t changing the geometric angle-of-atta c k of t he sec t ion.
The bla d es were a tt ac he d to the h u b wi thou t art icula ti o n except for col - lective pitch changes. No me c hani c al mechanism for cyclic p i tch was prov i ded.
The blade and hub c onnection wa s quite stiff re s ulting in a flap frequency of 1.4P at the design rpm. Figure 3 presents the b lade / hub bend i ng frequencies.
Instrumentation I The pitch moment, roll m o ment, and thru s t data w ere obtained from f o ur load c ells which were attached betwe e n the rotor hub and the supporting struc- ture. The load cells, located adjacent to the plenum chamber, were sub j ect to a highly variable t e mperature environment. In addition to the airflow m eter, the module contain e d many other s e nsors for temperatures, positions, and s trains. In the interest of brevity, these and the re s t of the instrumentation associated with the testing of the X-Wing rotor a re i dentified by their titles as listed in the s e ction entitled "Dat a Reduction and Presentation."
H ub M o ment Fee dbac k C ont ro l Sys tem . T h e c on tro l syst em is illustrated in fi gur e 4 b y a b l oc k d ia gr a m . T he lo ad c e ll s con t a in ed within th e t es t m od ul e were used as p it ch a nd r oll sen - : s o ts. Co n tr ol s t a bility m ea su reme nt s w e r e co ll ected dur i ng b o t h fi xed- and ro t ary-w in g mo des , a nd op e n-loo p Bode plo ts we re obt ain ed f or the c on t rol loops ass o c i a t e d wit h th e mom e nts a bout t he lon g itudin a l a nd l a te r al a xi s . A c om p l e te d i sc u ss ion of b ot h co nt r ol m e as u re ment a n d an a l ys i s i s c on ta in e d in ref e r e n c e 2 .
The X- Wi ng m odel used a c i rc u la ti on-con t rolled a i r f o i l on v ery sti ff non- art i culated blades capable of supporting the ai rcr af t i n f i xed- wi ng fl i gh t .
The c i rcula ti on control i s acco m pl is hed by b l o wi n g h ig h pressure a i r over a rounded trailing edge of an ell l pt i cal a l rfo i l , exploiting t he Coanda effect.
The ell i pt l ca l lead i n g and tra i l i n g edges are i nd i s ting u i shable w hen the blades a i rfo il prov i des t he n ecessary e f f i c i e n cy in b oth for w ard an d reverse flo w .
Fo r t h i s sys t e m, t h e lift on t h e ai rfo il i s a f un c tion of th e q ua ntit y of b low- ing ai r , h e n ce , r oll- and pit c h-moment control of the model can be a c hi e ved th r ough control of the blowing on all fou r blades. No me c hani c al cont r ol s u r - a re st oppe d, th u s b l o win g ou t ei t he r en d o f t l l e ma j o r a x i s o f the e llipti c al • f a ce or ac tua t o r i s requ i red o ther th an a nonrotating ai r valv e t h a t mod ulat es t h e ai r flow to the bla des (re f. I) .
T h e m os t co mpl ex p or ti o n o f t he f li g h t i s th e co n vers i o n from r o tar y -wing i to fixed-win g op e ration. The a er odyna m i c asp e c ts of t h e c on v e rs ion en c om p a ss conditions of relatively high forward v e lo c it y over th e advancin g blad e and r e v e rs e velocity over a portion of the r e treating blad e . Obviou s ly, as the ro t or is slow e d and stopped, these conditions are chan g ing con s tantly. For the X-Wing, the problem is not only to maintain sufficient lift for flight but also to assure a moment balance actin g a cross the rotor di s k, so a s to maintain tri m med fli g ht. Th e X-Wing desi g n treats t h e lift and moment balanc e problems by blowing out of both th e l e adin g - a nd t railin g - e d ge s lot s in th e mix ed f low re g ion and by usin g cyclic pre ss ure inpu t s which are c ontroll e d by a hub-moment feedback control system t hat senses the mom e nt s b e in g d e v e lop e d b y t h e rotor.
This re p or t p rese nt s t he res ults o f t he X- Win g m ode l t es t s ma de in the Ames R e search Center 40- by 80-Foot Wind T unnel. T he objectiv es w e re to determine the adequacy of the control s y s tem in maintainin g pit c h and roll moment balance durin g the start / s top s e qu e nc es , to a ssess th e abilit y of the blades to with s tand the stoppin g / startin g load s , to d e t e r m ine the adequac y of the control syst e m to maintain balanc e in the he li c opt e r mode, an d to as ses s the sy s tem 's capabilitie s in th e f ixed-win g m o de (Rotor Da t a R ed u c tion Sy s tem 40- by 80-Foot Wind Tunn e l. Am es int e rnal docum e nt b y Wayne Jo h n s on and F. Silva. ) A further obj e ctive w as to d e t e rmine t he s t a bilit y of t h e automati c hub-moment feedback control s y s t e m durin g all mo des o f fli g ht. Pr esen t e d here in a re ti me- hi st ory d a t a o f the severa l s u cce s sf ul st a r t s an d s t ops o f the X- Wi ng rotor a t h i gh for wa rd speeds a nd t he ste a dy - st a te d ata obt ain ed re la t i ng t o t he mode l a s rot a ry- wi ng an d a s a f i xed- wi n g ai rcr af t. Al so i nc l uded ar e the s ta b il i t y d a t a a cq ui red dur i ng open-loop a nd c l osed-loop hub m o m e n t f eedb a ck cont ro l sys t e m s ta b ilit y t ea t s .
M ODEL D ESCRI PT I O N G ener al F i gure I s h o w s t h e X -Wi ng mode l o n t he tes t m o du l e a s in s t al l ed in t he wi nd tunn el . Th e b alan ce sys t e m s t r u ts an d a n ai r d u c t to t he m odu l e w ere prov i ded wi th f ai rings to mi ni miz e the extr a neous ai r l o a da a pp li ed to the m e a - s u r i ng syste m . The m odul e pitch a ttitude ( rotor-sh a ft ang l e o f a tt a ck) wa s r em ot e ly co n tro l l e d us in g a n e x te n d a b l e t ail strut.
Data Reduc ti on and Presenta ti on Because o f the var i ety o f rotor operat i ng conditions im p li c it in the con- ce p t of the X - Wi ng , t ests w ere m_ de and t h e d a t a ar e p resented f or three oper-.
s ti ng r e g im es.
Fixed-win 6 mode- S t e a d y -s tat e d ata fo r t he tare m e as u r em e n ts a nd t he tested ope rati ons ar e pres e nted in a ppend i x A . T a b l e I presents t h e qu a n titi es fo r e a ch f i xed w i ng run.
TAB LE I.- FIX ED -WING MO DE D A T A D E F INI T ION S AND O R DE R OF P RES E N T A T I O N C olum n n o. Sym b ol s P arameter Units Col I V KT S T un nel veloci ty k not s _i MTUN Tun n el Ma c h num be r QPS F , q T un n e l d yn a mi c pr e ssu r e I b / ft 2 i i_ PS T Tu nnel s tatic p re ssu re ib / in.2 , i R H OIO0 Tunnel air density Ib-sec2 / ft _ Col 2 T H ETA R o tor collec t iv e blade angle deg BAR Barom e tri c pr e ssure in. H g PTC Total circulation control a ir g auge ib / in. 2 pr ess ur e WC Circulation control air mas s flow ib / sec TEMPC Circulation c ontrol air output ° F t em p e rat u re Col 3 XTEL Rotor b la d e trailln g e dg e airflow control actuator position RP O Plenum pre ssu re ratio PTP Plenum gauge pressure ib / in. 2 TEMPP Plenum air temperature °F WP Plenum airflow to rotor blades Ib / sec Col 4 XLEL Rotor b lade leadin g edge airflow control actuator position PT 59 T Re fe re n c e r o t or b la d e p e a k s l ot p ress u re lb / in. 2 o n t r ai l in g edge at b la de st a t i on 0 . 59R PTRT Re f e r enc e rot or b lad e p e ak g a uge p res- lb / in. 2 sur e o n t r aili ng edge at b la de root l b / i n. 2 X P Pi tc h cyc l ic a ct ua t o r p o s i t i on in.
CPP Pn e um a ti c pow er c o e ffi c i e n t; 550 (rotor pneumatic hp) 1 .68 9 qS (VKTS ) Col 5 ALFS, C Ro t or shaft an g l e of a tt a c k d eg P T 5 9 L R ef ere n ce rotor b l ad e pe ak s l ot pressure I b / I n . 2 on l e adin g edge s t b la de st a t io n 0.5 9 R VJR R otor b la de r oo t J e t ai rf lo w ve l oc i ty ft / se c i TABLE 1 .- CO N CLUDE D Co l umn n o. Sy mb ols P a rame te r U nit s C ol 5 - XR R oll cycl i c act u ator p o s i t ion in.
co nc l u d ed C MU10 0 Ai rf lo w moment u m co e ff i cien t m u lti pl ie d _WP) (VJR) by I00 ; 3 2 .174(qS) C ol 6 C L H Lift co e ffi c ient, a s measu r ed a t r oto r lift hub, -- qS CDE To t a l drag coefficie nt, dra g ' q S I FE Equi v a lent fl a t -p lat e dr a g ar e a ; f t 2 q AN G X / L In c lin a tion o f thr us t vector d eg CL'H Roll moment coef f icient, as mea s ured at roll r o tor hub; qS-'-_ CM H Pitch mom e nt coeffi c ient, as mea s ured at rotor hub; pitch qSc l l f t Col 7 CL Lift coeff i cient; q S C D D rag co e f f i c i e nt; q S side force CY Side force coef f icient; qS
y aw
CN Yaw moment coeffi c ient; qSb roll CL' Roll mom e nt coeffic i ent; pit ch _. CM P itch mom e nt c o e ffi c ient; qSc wh e r e : b = X -Win g f ix e d - b la de s e mi s pan = 8 . 839 f t c = ro t or bl ade c h or d = 0 . 051 f t R = roto r ra d iu s = 12.500 f t S = r oto r bla de p lanfo r m a re a - 70 . 7 f t 2 p = cu rr ent tu nn e l ai r dens it y Rotary wing mode- S t e a dy-s t a t e a n d dy n a mi c da t a for b o t h tare m ea- su r am ent s a nd t es t c o nd itions a r e pr e sented in a ppend i x B . Table 2 prese nt s th e q ua nt i t i e s for e a c h r o t a r y w in g r un .
T AB LE 2,- ROTARY W IN G M ODE DA T A DEF I N I T IO NS A N D OR D ER O F PRES E NTATION C ol u m n no . S ym b ol s Pa r a meter Un it s C ol I V K TS See t ab l e I , c o lum n I kn ots QPSP , q See c able I, c ol umn 1 ib / f r 2 MT U N S e e table I, c o lu mn 1 PST Se e Cable I, c olumn 1 ib / i 'n.2 RHI00 See Ca b l e I, c olumn 1 ib- sec 2 / ft _ Col 2 RPM, f Rotor rotatin g v e lo c ity rpm V / OR Rotor advan ce ratio TIPM Rotor blad e ro t ating tip Ma c h numb e r TEMP Tunn e l t e mperatur e ° F O MEG *R , fi R R o t o r b l ade rot a t i ng tip s peed f t / s ec i Col 3 THETA See Cabl e I, col um n 2 BAR See Cable I, column 2 PTC See table I, column 2 TEMP C See Cable I, co lumn 2 WC See cabl e I, column 2 CPCRIO0 Compressor horsepower coefficient; 550 (horsepower) pS (_R)_ Col 4 X2P 2 / Rev. actuator pos i tion in.
VJR See Cable I, column 5 PTP See Cabl e I, column 3 TEMPP See Cable I, column 3 WP See Cable I, column 3 CPPRIO0 Pneumatic horsepower c oefficient mult l - plied by I00; 550 (horsepower ) , I00 o S (f R )_ Col 5 XLEL See Cable I, column 4 XTEL See Cable i, column 3 XR See table I, column 5 XP See table i, column 4 WP ( V JR) CMURIO0 Rotor airflow coeff i c l ent, oS(_R ) z Col 6 RPO See tab l e I, column 3 PTRT See table I, column 4 PT 5 9L See table I, column 5 PT59T See table I, column 4 C P S I O0 Ro tor shaft h o r sepo w e r coeff i c ie nt , 550 _hor sepower) , I 00 mult i plied by I 00 , o S( fl R )3 Col 7 ALFS, C See table I, column 5 L / D Rotor l l ft to rotor drag rat i o ANGX / L See table I, colu m n 6 FE See table l, column 6 CP / S Rotor power coefficien t T A BL E 2 . - C O NCL U DED Col um n no. Sy m b o ls P a ra m eter Units ll ft i i ii Col 8 CLR / S Ro t or li f t coeff i c i ent , p S (n R) 2 pitch• o S R(_R) 2 thrust i C_ / S Ro t or pitc h m o m en t c oeff ici en t ; C T R o t or th rus t coeff icient ; o S (RR) 2
t
C NRH R o t or p it ch m o m e nt coef fici e nt, as pit ch m easur e d a t r oto r h u b ; o SR (RR)2 _ C QO / S T ot a l ro t ary po wer coe ff i c i e nt ; co_ s _u e C P
ps( ) s
d rag Col 9 CXR / S Rotor dr a g c o eff i c ient; pS(flR)2 y a w CM Z / S Y aw m ome nt coe ffic i en t ; p SR (RR ) 2 C TH R otor li ft coeff_" .en t, as m easu red a t ll f t r ot or hub ; 0 s(fl k )_ C PRIO0 R o to r t o t a l p ower c o eff i c i en t, m ul ti - p lie d by I00 ; CPS IO 0 + C P P RIO0 C Q / S Roto r shaf t to rque co eff i c i en t; (CMZ / S ) c os(ALFS,C)+(CMX / S) s in(ALFS , C ) Col I0 CYR / S R ot o r s id e f o rce c o eff i c i en t ; side force PS(_R)I r oll CMX / S R oto r ro ll c o eff i c i e nt ; o SR (R R ) 2 H force CH Ro to r H f o rce c o eff i c i en t; p S( G R ) z ,CL ' RH R oto r roll mom ent c o eff i c i en t, as m ea- r oll s ure d at r oto r hu b, p S R ( _ R) Z CQO / S To t al ro t ary t orque mi nu s i nduced and propul s iv e to rque; C Q / S - ( CQ / S)idea 1 Transient mo des- Co n vers io n t es t s , fr om f i xed-w i n s t o ro t ar y -w i n 8 m odes and the reverse , were c ondu ct ed a t several wind- t unnel condi ti ons. F ig ures 5 t hrough 1 8 show tim e h i s t or i es of t he s t ar t s and s t o ps for which t he f o l low i n 8 quanti ti es were re c orded. These tim e-h i s t ory plo t s wer e 8e n e ra t ed by Lockheed- Cal i forn ia Co m pany fro m d i g it al da t a prov i ded by Ames R esear c h C e n t er.
TABLE 3.- TI ME HI S TO R Y PLOTS Pa r a mete r Un i ts F i gure i_ Ro t o r az im uth s i ne ( _ ) 5a-18a Roll cyclic error V 5a-18a P it ch cycl i c error V 5a-18a Rotor roll i ng mom ent i n.-lb a 5b-18b I R o t o r spe e d rpm 5a -18a Ro t or p i tch i n g mo m ent i n.-ib _ 5 b-18b Ro t or shaf t t orqu e i n _ -lb- 5b-18b I Ro t or t hrus t Ib- 5b-18b Pilo t inpu t ro ll c o m m a nd V 5c-1 8 c Pilot input pi t c h c omma nd V _ 5c- 1 8c R oll 5 c - 1 8 c cyclic actuato r i n ._ Pi tc h cyc li c a ct ua t o r in . 5 c-18c Blad e flap bending mom en t, bla d e #I c uff in.-Ib 5d-18d Blade cho r d b e nding moment , bla de #I at cuff in.-ib 5d-18d Blad e to rs ion ben d ing mom en t , blade #I at c uff i n ._ib 5d-18d Bl a d e featheri n g angl e de g d 5d-18d Bla ( e f l a p b e ndi ng mome n t, b la de # I cuff in .- ib e 5 e- 1 8e Bla d e f l ap bendin g mom e n t , blad e # 2 cu f f in . -Ib ? 5 e- 18e Blade flap b e ndin g mome n t, blad e #3 cuf f in.-Ib _ 5e-IS e Blade flap bendin g mome n t , blade #4 cu f f in.-Ib 5 e -18e Blade cho r d bendi ng mome n t , blad e #I c uff in.-Ib 5f-18f Blade cho r d bendin g mom e nt , blade # 2 c uff in.-Ib 5f-18f Bl a d e cho r d b e ndi ng moment , blad e #3 cuff i n .-Ib 5f-18f Blad e cho r d b e ndin g mom en t , bla d e #4 c uff in.-ib 5f-18f r Load c ell th r u s t ib 5 g - l a g i_ B la de tors ional mom en t , blad e #I 40Z r a d ial st a t io n in .- ib 5 g-1 8 g B la de c ho rd b e n d i ng m om e n t, b la de #I 25 % r a d i a l s tati on in . -ib 5 g- 18 g B l ade chor d bend i ng mo me n t, bl a d e #I 40% rad i a l s t a ti o n in . -ib 5 g -1 8g Pl enu m press u re Ib / i n. 2 5 h - 18 h T otal p ressure t ra ili ng e dge du ct , bl ade #1, a t r o o t lb / i n. 2 5 h -l a b Tota l pressure t ra ili ng edge duct , blade # 1, a t 29% rad i al l b / i n. 2 5 h-18h st ati on Tot al press u re t r a i l in g ed g e du ct, bla de #! , a t 44% r a d ial l b / in . 2 5h -18 h s t a ti on • , L sen s or s .
_As ob t a i n e d fr om t he model mom e n t and thrus t i A s com m ande d by mode l au tom at i c co n tro l syst em to dr i v e t he cyc li c error sl g na _ (fig. §a ) to zero.
_ Fr om stra i n gauge rot o r shaft.
_ od e l has n o cyc li c feat h ering syste m , s o sis na l reflects l ooseness of coll e c ti ve sys t e m .
e p e a t from fi g ure d.
o re scale ch an ge.
TABL E 3.- C ONCLUDED i t L i J i i J Paramete r Un its Fi gur e i t t _ i Sta t i c pressu re t ra i l ln $ ed g e duct , bl a de # I a t 44Z r ad i al ib / In , z $ 1 -18 1 stat i o n Stat i c pressure tra i l i ng edge duct, bla d e # 1 st 59 X rad i al lb / £ n . 2 5 i -18 i st ati on S ta t i c pressure tra i l l ng e d ge d u ct , blade # I a t 7 4_ rad la l 1b / I n. 2 5 1 -18 1 s t at i o n S t a ti c pressure tra i l i ng edge duc t , blade # 1 a t 88 Z radial 1b / in . 2 5 i -18 i T o ta l pressure t ra ili ng e dge duct , bl ade # 1 at 5 9 % rad i a l l b / in. 2 5J - 18J I s tat i on s t a ti o n i Tota l p ress u re tra i l i ng edge duct, b lade # 1 at 7 4_ rad i al l b / i n. 2 5J-I RJ i s t a ti on _ Ro t or b l ade t ra ili ng-ed g e s l o t de f lec ti on , b lad e # I at i n . 5J- 1 8J b 29 _ rad i al s t a ti on 1 R oto r blade t rai l in g -e dge slot def l e ct l o n, bl ad e # I a t in. 5J-18J
!
44Z ra di al st a tio n i T ot a l p re s su r e , t rail i ng edge duc t, b lad e #I a t 59 % r adial i b / i n . 2 5k- 1 8k !
s t a tio n T ot a l pres s ure , t ra ili ng e d g e duc t, b la de # 3 a t 59 _ r adia l ib / in. 2 5k- 1 8 k st a t i o n T otal p ressure, t r ai l i n g edge du ct , b lade #4 at 59 % radial i b / i n . 2 5 k - 1 8k s t a tio n T ot al pr e ssure , t ra ili ng edge duc t, b lade #I a t 7 4Z radial i b / i n . _ 5k - 1 8 k s t a tio n T ot a l pressure , le ad i n g ed g e duc t, bl a d e #I a t 59 Z rad l a l 1b / i n. 2 5 £ - 1 8 £ i s tatio n T ot a l pr e ssure, lea din g ed g e du ct, bl a d e # 3 a t 59 X radia l 1b / in. 2 5& - l S & st a t ion T ot a l pr e ss u re, l ead i ng edge du ct, b l ade #4 a t 59 Z rad i al i b / i n . 2 5 _ - 1 8 _ s t a t i o n Tot al pressure, lead i n _ edge duc t, b lade #1 a t 7 2 Z radial l b / in , z 5 t - 1 8 t s t a ti on Ro t or blade t ra ili n g -ed g e slo t deflec ti on , blade # 1 a t i n. g 5m-lSm 59 Z rad i al s t a ti on Ro t or blade t r ai l i ng-ed g e slo t deflec ti on , blade # 1 a t in. g 5 m -18 a 7 4Z rad i al s t a ti on R o t or blade t ra i l in g-edge s l o t deflec t ion , blad e # 1 a t in . 5 m - 1 8 m 88 Z radia l s t a ti on St a t i c p re s sure , t ra ili n g edge duc t , blade #1 at root l b / i n. 2 5m- 1 8m where: _ = reference rotor b l ade azimuth ang l e w it h respect t o O " over e mp enna ge ....
Du r in 8 p re s alected t e s t c on d iti o n s , t h e D yn amic An al ys i s S ystem (D AS) was u ti l i ze d t o assess on-lin e t he h ub- m o m e n t f e e dback c o ntr ol system s t ab i l it y.
T he measur men ts recorded ere lis te d in table 4 a n d t h e Sod s plots f o r the ta bul a t e d cond i t i ons ar e presented i n f i Eure s 19 t h r ough 61, Fr om these p lots , t w o im portan t par a me t ers, ga l n marg l n and phase marg i n, ma y be ob ta ined wh i ch d e f i ne th e re l a tiv e st ab ilit y o f th e co n trol l oop under exa m in at i o n . _ G ai n ma r$ i n i s def i n e d a s th e mag n i tud e of tr a nsfer fun c t i on ( i n dB) eva lu at ed at the frequency where the phase angle is -180 °. The phase marg i n is defined a s the phase a ng le (de g ) above -180 ° st t he g a i n crossover frequency ( i .e., dB " 0). 2 '3 i TABLE 4.- HUB MOM E NT FEEDBA CK CONT R OL S Y S TE M STABILITY DATA Feedback con t rol loop co n d i t i on F i gure Run Po i nt Rol l l oop P i tch l oop 1 9 23 20 O pen S t ab ilit y t es t 20 23 38 -I S t ab ilit y t es t Open 21 23 38-2 O pen S t ab ilit y t es t 2 2 23 38-3 Cl osed Sta b ilit y tes t 23 25 9 Open S t ab il i t y t es t 2 4 25 I 0 S t ab i li t y t es t Open 25 25 II Cl o sed S t ab i l it y te s t 2 6 2 7 16 Op e n St ab i l it y te s t 27 2 7 17 S t ab ilit y te s t O p e n 2 8 2 7 1 8 Clos ed S t ab ilit y test 29 2 7 1 9 St ab i l it y t es t C lo s e d 30 3 4 14 St a b i l it y te s t Op en 3 1 3 4 1 5 O pe n S ta b i li t y t est 32 3 4 16 S tab il i t y t es t C lo sed 33 3 4 1 7 C lo sed S t abil it y t es t 3 4 35 3 S t ab i li t y t es t Ope n 35 35 4 Op e n S ta bi l i t y t es t 36 35 5 Sta bilit y t e s t Clo sed 37 35 6 C lo sed S t ab ilit y t es t : 38 36 4 St a b ilit y t es t O pen ' 39 36 5 Cl osed St a b i l it y tes t 4 0 38 8 Sta b ilit y t es t Open 4 1 38 9 Open St a b ilit y test 4 2 3 8 I O Open St a b ilit y test 4 3 3 9 4 St a b ilit y test Open 44 39 5 Open St a b i li t y t est 4 5 3 9 7 Open S tab ilit y tea t - 46 3 9 8 Stab ili ty t est Open 4 7 3 9 9 St abi lit y tes t Cl o se d 4 8 39 11 Open S tab ilit y tes t 4 9 39 12 St ab ilit y test O pen 50 39 1 4 Open S tab ilit y test 51 39 1 5 St abi l i t y t es t O pe n T A B L E 4 ,- CONCLUDED i Feedback con t rol l oo p c o nd iti o n F i gu re Run Po i nt Ro: l loop P i tch loop 52 39 21 S tab i l i ty test Ope n 53 4 0 16 Open St ab il ity t e st 54 4 0 17 S ta b ilit y t es t Open 5 5 4 0 1 8 O pen S ta b ilit y t e st 56 4 0 19 C lo sed Stabilit y t e st 5 7 4 0 22 Stabilit y test Open 5_ 46 5 Stabilit y t e st Op e n 59 46 7 O pe n Stability t e st i 6 0 46 8 Cl ose d Stabilit y te s t 6 1 46 I I Open St a bility t es t C O NCLUDING R EMARKS Th e t e st o bj ec ti v es a s se t f ort h in th e intro d ucti o n o f this r epo rt w e r e su c ce ssf u ll y m e t . The X- Win g cont ro l sys tem w as a b le t o mainta i n p itc h- an d roll-moment balan c e in the rot a ry-wlng mode and during the s tart / s top s eque n ces , t he bl a de s w ere ab le t o w ith s ta nd t h e loads encoun t e r e d in t h e st a rting a nd stopping pro ce du r es, a nd the ca p a biliti es of th e c ontrol syst e m in th e f ixed- w ing mode we re d e termin e d. T h e a u tom a ti c hub - mom e nt f e e db ac k c ontrol syst e m d e monstr a t e d a d e qu a t e g a in m a rg i n f or th e m aj ority of th e modes o f f li g ht t e st e d.
II APP E ND I X A FI XE D WIN G MODE STEADY STATE D A T A 1 2 _c o o N oo ,o o _ _ . o c o o o _ • I I I Ill II ! I I
1 4
, ,.L I ' A_I_ 1 8
I i I II II t O 0 . I I I I I I 2O el • el • !
_ m _ ,_ oo_ _,_ _o_ _,_ 0 I0 I_ I 0 I 0 2 3 ............ j O0 I I I oo • + _ _ .... 0 __ .....
O 0 I0 I0 + , i J 2 5 L ......
I I I III II t!
| 0 Im(_ Q.] • • " _" * • I I I I l i II
L ......................................... ____
3 O i +b
i!
!
i
! ! I O I g i I • i i o O I0 o ¢ tO I _ i I I! I II Ill III
i'
I !
i "
3 8
ll t Ill _ cel l o e o e _ o _ i _ I _ 3 9 4O L II li
!
" d _ d d d _
_I,. O,-,, ___ o_ o _ ,..._ .. _ C _. 5" I'_ _ '_ I 14_
_,_ _ .... = .-..o
_ dd _ _ d g dd
_ 0 II Ill II III 4 8 il J i, , , I I
4 9 i
i
_ ........ J
| II II tl II 5 O i II
$ 2
t
! I
I
i !
I! |! l!
C ! ! !
_ 7 • I r _ • A l!
APPENDIX B ROTARY WING MODE STEADY STATE DATA 62 , r - _ i '-_ 6 9 L .
_ 73 , -- * - @ R I C ;I _AL PAGE 1 8 0 _ " POOR Q U ALI T Y 74 _ , 8 - •
L
r 79 _ T - 8 0 _'. 81 _ 82 i i - ORIGI NA L P A t ; E I S 83 O F POO R Q t / A_,I ' ft "
i
L ............. _ .................... J r- • . a I- ee ¢ ," * • * 4 • cO0 * • e_C o • e_ (: * C C I 0 C C ! 0_ ' O _ * = * 0 -- o r ,,, *- , a ! I I g I | • * 0 * * * _ 0 • GO 0 _ G ¢::: C )- ).
t _ UJ } _ , = a .. a ,'*" _ 0 f... t _ I '.. N m t.J .j.j,_ Q. 0 _@_ m m a % 0 0.- , f t _ .. A t. . - .. . * 7 _ t .. * 1. !
ua uJ r (I _ • ¢L Z _ •..- 5' , .* _ , .. o , - .' _ ._ $ ,- z i i C- O R I O N A L P AG e; _S 01;' -P( x )R Q U A I , I] y : + + 9 3 .
I I I I I I I I I o I I I o I • * 0 • • * ¢ * • • 0 • * e 0 • I I I I _ I1 0 l im I1. I1_ Z _ I_ _ i _ _ I _ _ _ i _ • .. . . _ .. . -- _ _ n
k
I 1o2 i" 103 _ - _ lO _
• -' "' ** "° " _ ' _"i_ _!_ _ ' i * _" _ii_ *" "_ *
U_ _ _ • *¢ Oe * *Q • e O _ . , e O 0 * e oOC o 001 0 _Ol_ 0_1 I I OI g ! I
-- _:_ --- o - _o o ._
O0 0 O0 0 O0 C I I OI I • * _ * 0 0 0 o • * 0 * t I O _ . _ . _ _ ' .. _ . _ .. _ • _ • _ _ I I * _ GG _ . .. _ ' _ __ _ _ . ......
I Z ¢ i _ , _ : _ . _ _, ,, . ._ .
||0 ; - 11 2 II_ _ d d g d - o [ - 1 1 6 . : : - , r ' - 117 118 [- _. 12 4 _ - 126
r
" 127
zze OIUOINAL PAO_ " _
130 r 1 3 1 F.
1 3 2 1 3_ [-- I --" 1 3 9 i t ' H FEI _ NCE $ 1. Potha s t, A.: X- Wi n S Stab ili ty a nd Co n t r ol Dev e lopme n t a nd Wi nd Tunnel Demo n str a t i on T e st s -- He l i copt e r Conver si on and F i x e d Wi ns Fl i shc.
Hel i copter Soc le Cy , Nay 1 9 80.
2. Chopra, I.; and Ballard, J.: M easurement of Control Scab i llCy Character- i sc l cs of a Wi nd-Tunnel Model Us i ng a Transfer Func ti on M ethod.
Paper No. 80-27, Proce e dlnss of the 36th Annual Forum of the American Presented a c A IA A llC h A erodyna mi c Test l n g Conference , Colorado S p r i n g s , C O , Ma rc h 20 , 1 9 80.
i 3. D ' Azza o, J. J. ; a nd H ou pl s , C . H .: Feed ba ck Contr ol Syste m An al ysls a nd Syn t hes i s. Sec o nd E d. , McG r aw- Hill Boo k C o . , New Y o r k, 19 66 .
Fi g ur e I.- X-Wing r o t o r in s t a ll a tio n in win d tunn e l.
PNEUMATIC DUCT
s_ .o-r __ ,_ _ J - co A .o A
/
BOX BEAM STRUCTURE SURFACE _ .
F igu re 2 . - X- Wlng b l ade cross sec ti o n .
m4 2 U R I G I N AL P AG E I S
O1 _ POOR QUALITY
............... r SP (SP-7P)
t _ 0 (4P-eP)
N z_ W (J 4P 13P-SP) Z UJ O ILl cc u. 20 31 ) (2P-4P) (.9 Z m I- < LONG. MODEL I...
O 21 ) (1P-3P) rr Z O 10 Z LAT. MOOEL
1 P(oP-2P)
LAT. STRUT LONG. ) LA T . BALANCE 3. j 0 2O 40 6O 80 100 ROTOR SPEED, % 1 F i gure 3.- Ro t or blade / hub b e nd l n 8 frequ e ncies.
' R.
, __..:_,,t , : .... I ,i .1 .,._ - : t;-_I , ,.-"_.. L-c ' li': _--- / ..: , ' c. Z.. ' ......... , _ - I .... Z " ' _ O .... I ........ . .......... -........................ . ,. _...............
JL -.,....-.-.... , .----_! ' - ' _ _ . , I , ,, , ,, _ - I " I . _ _ I . . --/ " ',_ -- -- -' 1""_-_t ' • '1 ' ' , ' _ '" i .... = _ .. i . . _1 .......... . ., I ""_: ..... _ _ ' -- _ a 1........ -. = ! .....
.... 1 .................. 1 ..................... .1 .......
.... i,"_ Z ._V-:. . l-_-_.;: . ,..:4--;t . :- . I ...... : - :t........ :'_ : ,, _- n i;_-!:": '" ::_ - r::-".' , '_":"F"--f _ ........ _ ...... .. -. t ...... '..... ": :' --
, . ! _ _: ; ..... , ,,._. . .. , .. __
__! _: _:I:1 ' ' "- ' ...... _ ._
•.r. - I ..... I . _- .,._.-I ......... __ ..... : ; ...._. . . , , . . _. . !_. : ' _._ _.: ' .., , .-_- .: . ._ . ........... ill .... _ . _ ............ . _ __._. ._ _. : . . . ,,.__; : - - ........................... . : .... -.._.:: r . :.;. : -.... _r_ _ •
_-_ - . _ ill ,. :i " _----- - . _ .... _ .... -L. _ °
' - ,,- _- L- _ i ..... - .+ - . _ .... _ , _.[___. .... _ _ - "-_ : _ ' n_ _ n ........................ ii: ' :-:t:::,... ........... _t ............ ...... ::!:":_ . . . . _ _ . ._-_. . . . ....... :_:. . ,_' .. . . ' . ._ , __ " % _ ,_ _
.... , HI I ........ _
,. _ ! .... . ..
. -- _. _ . . , .... ! .! _ , ....... _ _ I_ x j _ i ........ II ....... = '_ * ' lr"" t , - I _ ' r' ' ' n_o,,,,, ........................... ...I. ....... " ..... " _ .......................... ....._ "T"". _ . :!" ................. ..... " :; , , _ _, , ; _" ....... ' i . !'"" -- _ o _n _ ° T ; 1 - "hi. , . , ..... _.-._ I' i , 7T_L- - @ ' ' "" _ I
Z-_W.__"
....... J" . . , . . _ ...... I ......... ,........_....... • , _ ; .... , , • , _ _ ----_.--_ . .._ , ' , ....... _ . ., t • -_.. - r ' ," I ...... II : ..... -_ ,. . ._ ..... I . • _ _ . n _ , Z: ..... _'=i7_ ..... :. ' ..... : ' , :, 11 :. : i"::::-_'_-:' . :i:::___-'"i+ii : 5 " ":::"_:. - _ " _- " :._ u . . !.._ . :.. ......... Ii.....
..... Ill ....
I I' " , i ........... . • , , ' .
• _ ........ :...:..1_ ........ , ............... _ ....... , ...... . ..... _..._ ..... _ ........ . - .-._-_-...... I..
_ i I # _ - I • .l l . _ ' '| ' _' " - • • ._ I ' / t '_ I ........... ' "......... ! ' _ .....
- . |...... . , .... ,. , _ - .....
, I ' " i .... ; -
! ' - " 4"
_ .... " ......... W ' -- L "F - "'_ ............. : - ' : , _" : f" " ":": "" ' :'
:: i " "1 .............. _ ....
N p . - ' ,I ......... : ' ' ' ' i 0 • ' ,_ , , 1 .... l_. & -_ , :, _ - _i: , .L.
,,i '''! ' "- - ' " v "_ i " ''| v u _ u u v _ o I o . o l o . o i o o . . ..0., .
I_ oM.M ( ...........
!
i
I
i'¸ ; o.
,, ..... * ' _"_' : '-._.' _" _D_, _ " .............,,,"i '""i,, , ...... _IT _ " ... ....; ...... "_' L _"'_ "m_i_ : :. . ; "_._ .............. _ .... , . . .__._,_ ' : , , .o..; ........ . _k _l m
.... l_ . I ., I . ;, .. _ .. _ . . ±_ : - ' _ , , . , _: .. -I _
................. 1 ................................, - .................... ..... ......... - r ...... i - . .. I ., ,_ ..... , ........ _ .. , _ ..... _ ......... ,In , _ . . .: ! , ......... , _ . I. . ; _ : . . : .......
I ' _ _' ' ' ': '' _ :' ' ' _ ' ' ' '_ ' '-- _'__,---r-- ...... ,'--_' '__ . ' ' --L '-- I.,,r.; - '_ • .,1; .... : , . ,_ i ..... _. ,, ,. _ ......... ;.
• ,"--:-.' ; :1 . , , . , ....... _ .... I.... _'-r- - ._ : 4": . ! : _,, t; Z- _I:_ , t,._ -/e , I.._----,_" . .. , . _ ., ; _ ,, _........ . .; ; . -.. . , , ! , _ _. .... . _ ,_ ,.,
...... _"":'_: ........ P_ ........ : i......... __-.* _,,--_: ...... _ . ..... _- - M
' , ...... I ' ' _ ' _. _ l ..... .'',l ' ' !_',I .... ,_I,:, III , , z"2 " _ F _. _ _ ...... ; t+: ' _.- . -'ff_, _ , i . .. __-.fz:L ' .:; ......... =_-_:. ...... _ . _ l - ' --"t - ,L _ ::_ ; - - _ - " i _' _ -' T'_m !:'.',:7"_ 1 ':_ ::. ! ' _ . I.
+-.-_ I.:..i , ,.. I, . . ,_ ,. t, ;. _:,.I " ; '1; _ '_ ' _.. , ' ... / _' _ '_"+ I , ! ! , : . " , ' _1,_ i : -,, - , _ I, , : '., ; • • , , _."" ' : ' I , • _ _ : • I ...... I ' " ; " " ' _ ' ; ' : _ _ ] I ; : / ' ' ' I ' ; + m ; .%_ . : I, :i :, '. : . I ........ :.1 _; . ;_ .... :,i, • _ ' !l' - t ' ; ' t ' ; : / I ' : _ i ! i t t ! ' ! , : ' I ! ' i . t I i ; : _ : ; _ T .... :l . _i _ . . , _ I t 111::: ' ,: '. d,,: . l'_:ill]: ; _,1 ; _._ .I ,..1:., - r = . . . I :. ; _ . , ' , . _ I . . , ;:: , ; , . ; . : :: _ ; . I , :. :I._ i ,_q .:, . .: ,,_1: ' -_ !.... _,_,1,,.i . ._ _ . , . !,-r_t., !:: /.
_ , : - -i _ - _L:-!! - i-: : , i i . 5+i- -: !_!_ -:: ! - . -.- : . : i : - . - _l_ -;: - - l: " : - - 4 - ; - i_:-;-_ .: +: : i - u . i- ,,, :: .:.. - _.:: 1 ::: : i::!l_ , !il! : i!!::! !,i!i;!_ - _:?i? i:: : i !!_!!:l!i!!!!!i-/ . , ; ._, . 1 :. . I,, , ; ; . - 1.."_1 .... I . . i.. . _"*'_m_. . _ l ., ::1.; ;;_ . 1 . '_;. .I. ,:.I .; /0 - .... i_ 1 :; ' i:; - i_: ; l_',_]: _ ' 1 - : ; _ ' : .... I:' , :I! . .. . ' . , . , _ ._ F ,._ . ._ / _ -:'', " - --i " l ' _'.... IL_ * '_I ...... _ N ';_q_' _t ''' _, ..... _' 1 '''', .... : / _; i:_t. -: .... _ :::i : _;:::L_:I: ;I::: _:_I L _;:I:::I _:::i_ . : . 1 ::;:I::: -/_ _ _ -- _ .... J "" - I , , : : _ .... i . . ; : i : . i I ) J , , t- , : : . I_..... _ _ . ; _ . _,I. _.... 1..... _ . , . .
/
• i_r I ",: ......... 11_.:_ t'_" , ...... !:"I " ,_' : _ : ' ," : _I _ __ I ' 'll : .... ;' _ : P : : : .; ' '' , ' ' '
• :: : -" J ::: :::::_!:::lI-ffl :: :: * ::_".:: : i *::_ :/:1::: ::: /
| _-:._:_ j. .i_i L _ L , _i.:i.:. : . . ; . i.i :.i : .._i. : _ ..i .. i. _. .:..i._. a ..: ::. . L i L . i LL , ". ......... ' : .... _ ........ + .... * , , .I, . .i I _1: _ I_.q , i ,i_. !.. I .,_ :1, . .... L, - , 1_ : .,_ I . , 1_, ; _.,, . I..M_I • I,. _ . CI .... I :, , . • ' !'l'_- - '_r' ' I ' ` ' /
.... .... 1 ......... ...... +. . I - . ; .... L
:': ,_g._:t:ri', i:;;1"_-:1 ;i' . : ::::t::__:::+/ : ; :_::;I . :::i:::-- / ° ._ !2-:!: I : ..._1 i,, ; , ,, :_l ; ,,,;li.; ,;:_I_ : ,!,.: L=.
• , , , • , , I • , I I ' • , , , " - o
- ? = = - ? = = - ? o o . - ? _ ? "
1 1 I 1 | l 1 ;
- _ - _ - . __
_4 9
i't J, r -
" ' ii ....I ...... :_1_1 ,_. ...... i......_ . I_ _. ' - f_
'i ............ t c _'' i i _' _ .... : !: = 1"_
;! : - - - ! ' _.17' 7 :""rl . _. £_., .... ._:i. .... .... . -- ---'J ' Z: _ ...... :_" " ' _." '_, _ _ - °' .... " . ._ _-._":___: ...... ' -" _ i -- B , _ _ : -- . ;-- ,-- - ,___ , . ' ; ::I i! i-_ !-i !.x _ i _1 ! -'"_ r.
____ L . _ _ I . " .... _ _.__.. L _ __ .
......... i ..... -._ . ._ - . ._ .... i.. . I....... i ...... , ........... : .......
-'.---_. : -r i _ _t- -- ,_--'H--F,.- ' -7-11--F--_
I I_ ......:.................. - ' . .... !............ _ . ..: . I : . :.............. = ...... . ........... _........
.. i i : .....
........ t i ll _ ' i i I ' _ i _ , = i ' /. I - " _ f l ' " p • : ' _ J _ . ' J . _ ,el I ] i i Ii i : ' t:: i'l _. : 1: ' . : _ . ' ........ L L _' o
e ,_ . ,_ e , _ _ I ea , I ,_ e _ i _ _ " '_
I _ - d i d - d W d -- d I d d • I M i i L_ *II-M 1_ 2 1 _ 11 _ 111 _ 11 nP qr _'_'_w_+_'+'_ r" " ' _'_ - - - _ _ - : 9 : , , I ._ r ._ .w _,_ .... •.... , ...___ _............ _ . _ . . _++_ . _+,_ ....... , _. =_ . ........... _ . _. _ . + , _ , _ t" ' ........... _ ..... • o .i i _ ' _ .... " , , • i N ..... ........................................! t....
• .... ----- 4 ..... t _ . _ _ ..... . .
' . '1 . ! + ' :: I :'A I : (. i- 1 ' t : , "_ : , - /_ ......... i' : 1 ....... ' ..... _4!' <: _ I q .... , ._ , l -- L ''J ] : - '. : ...-1 , :_" 1 .. . . ..... 1.:....:.. ::...... _ - :__'""-I .................. t"''; A ...... -i" ':: " --P _ " , - ; .... : ...... , ,, _ :: _ ........ I .... , ' 0 •] - ::..: :. 4: +..;- : ...t.;-:. . :- :. - .:-:.i ..................... , ..................... t..... :" - !"'":-- ®
• , _ ........ . ...... _ : • . I .. I . . o
q : :q, ............ ,, :) --1-
.......... .... = _ f 7 ' " " _ " I , 41 . .. : ..... t i : l ._.:+ : :. : ::.: . !::_. . - i ....... : ..................... ._. - . - . . _ ........ _ ........ ,- ...... t ...... _ .. . - .
% .. ........... . _ .I ...... I; _1 .... _ ! ' "r - '. : . i . . ' t. .; , _ • _ " -" l m| - . i ..... _ : :i- ' ' _ i " :. ' : - i ' rl i : ' I._ . .. - • "' : ' :: . :: .. :. -[: :. _ ,-- . : . -:. . i ::: .. : . - - - + .:. - J. : -.. : _. . l : - :-: - - : _ .............. i . .............. :i - : .... <_ .
i
"_ I !: ; , . _. _. - _ .........
' , - .... ; . -- _ _ , .................... - i : - - " " : ...... : ............ 1 _ ! . : . . : . , . ; :
......... f_ t , . ' :t ...... _ ..... o
_" , - . : : . : -'1 : : : : : , 1 i ' ; ;" _
: ..... : ....... . .- : + ............... l - . -- ' q ............................. ' ' , - . + :: i ......... _ ' .............. .... + ....................... . .- -I- :-"
( _ 1 : _ : _ : _1 _ : i _, : . /o
: '_ I • , | 1 : ' [ : I ! . ' . , " ; ' -- I " . _ " -- - _ . - _ , I : ., . _ '; " :% ", ' ' : '+ " I- , ' :! ' ; I • ' ' . i . : + • . , , ( I , _i _ ..... + I._.
. _ ' t _ .... I : 1 " , X . _ • / .... • I .... _ [ ........ . : + ..
,: - - . + : ...._ ............ _ ........ , - -_-1 .... , ........ _ ..... :+ : ._-t ..... . , , ,. I" , ?_ _ .__ .... " - t, ill , . , . I
• i . : ! " ' J [+ ...... .i ... .. - _ ..: . : - -J . -:......... . _ ..... ;-- --
• + , . .... : _ ,, ........ +, ....... ............... , ............. : .... . . ..: ,..... ....
• . : • . , . . . ,,,, ..... . : :: .
. , ", 1 , , ! : J + , t L il..... + , , i_l . ,: . -
- ,, : !_-4 - -- ,t / I -- - - t -- -, - . :: + . Xl : : - _ ' ": " 1 ....
.... i' "
' ';;I;, , i _ ' ,- : ..... , i ....... _ - I , I I . I I _ t, - - _, o , . ,.C " + ' c + _ o o I ? 2 !
l i[i i i I 11 :: - -" . .| ; ....
, , , r _ " ' [ : " o ...... !........................... i " _. 2 ik-Li L :_-.
, ' [ i ' ' " °
, , • • : , , b ..... , i I O D
;:if ......... "..... :.......... I.................... :::-" ' .... 7___"
r' i : i:::[ .......... .... . _ ....... ; ....... 2 .. ;._.. 2 .L L .-.L; .... ' ..... I" • ' _ : "'[ ........ 1 77 " ' 77i ..... T' .": 7 .................. r .: ..... i ...... [ ......... I' ' _ • .... _ ' "-- I ........ _ ......... I ...... i ' _ " I ",, ' : I .... i'' : o , _ ........... i . . t - . r -..... _ :..
t J | ' ' "_"_ _ _ ' " " * .......... ' J - _ , l':"i'" _ I _... ,.. . ., .:{. : .... i .... I ' _ i /
l
!
L
; ..... I : .... ! " :";!',: : ............... l"; - ..
" ........... I ,....... ,...i .......... ,_.1 .... ;.... / _ '
" ' , ..... : " • \ • : ..... ._ .... I. ; :.A'- -- .±- _-; -- L_ ..X_. I LL'_ -- -L:'-'_" -- I-- • ................ 7;7177 :-: ']"- 7-_ 77-;71 ........ :'"" 7". T 7] .. _: ._ : .. -_r[ . .. i .... " _ ,.. " : ..... !'''t _ • - I ....... I ..... I .... t ' ' !' ' ' I : ]- .... I ':': .... : I_ • , :: : :: I : : _:. . ::!::::. 1 ::i _ :..::_: ; :1::;:_::i - o = .............. I .... i ....... _ _ "% . : I .... _" l.,., ' - ................ I ....... _J_ l : '-l " -- _ ...... _, I . . _..... _.... I ,,._ • ::::1_'7: / .... : ... .
.................... .
?
........................................................... _.: ................... _........... :-, i . ..... - r ....... ..,' ..... .... .. ,...' -- ' _' ; .......... t l .... ,' - , ...... '' • _''',- I '::1 .... "" _ . .......... _,1... i ...... :::. , _.:. _: 1 ::::!::: ......... _- ..... _' ...... I" .................... '_........ l - ............. -I ....... - ....... I- ............. _ ......... ¢_ . I ...... _ .......... t . . . ! ..... _....
...... I ..... I ...... I. • _ • :. I._ 1 .: .. I. : _ - - " --. , " , 4 ..... , .... , ..... +1 ........... . , 1,t ........
. . ' .............. _ ; ......... _ • .. _ .. t .. .
. , .... ...... :.; , .......... I .... _!" '' =. i _........... ! .......... , _,
" ................. ! __ ..... " -
_ , ...... , .. , ..... , . ...... , .....
o , -----.- 4 - _ -- _ " , . .I ! ..... ' . '. .... - " ' _ i ..... I .......... ..... : . : , , . _ ......
I ,- ._. : ... _. ...... i..... .-:i...._ . ._. L =. i_. . . . L._i._. I L L . .i . ..i . !. . . _ . , T "] " : : :::: :!: 1 :i:_:: :::; " ] :;: / :;: :::: s ........... t ...... : .,i ........ "_ . . ] , I_, i J
= " i1 : !.. :1 ' I . . _; ; ,,t_::d,:..l "o
, , , [ , ' I , , ii: _ , I _
. !
| _ 7 ORI_ G / 'N,&I, P A c _ lb .
P t k ) l ¢ qU A,.. " ; i_
L ........................ ..... , ........................ _ . i
I
i- I - ll 1 7 0 o
i ii..... ;, i}: i li '
' ' i
_::_ _ii!ii -:_: i_ _ ii -i i:_ i_ /, , , :_ _. _
'TI "" .................................... ? T T' , ";'_' ,'" - " il l ;i:i iIi m ,, , ; .... o '" ,,, '" " , : . ,
if ............... ; " : :i!!i !!ii _ -
........ i .................. 1.1:,,,I .._ ;,''i ...... '' i!, o : I;:: : :!::i; , :::: :,::I: :::r ',: I ; I::i!:::. _;::I,_ : : _: ', : :i - ' ..... ' ..... ' .... , ...... ll '' ...... l .... / ........
........ "TT........ "TT1"TTT_ :TI'erT:"F :'"'"i ........ 7TI" T " '.'!" " '" 'T ''Ti ':it ....... _":'"" ':':':t ] i": '. 2 ":" ,_-- "r ,.
. ,_, .:, . :.:1:.:, , .:.... , ..::, i , ! . _ ....... _
, I, , I .... l' _ ' l :: " . l ........ _ .
.... "_ '1 .... "_ ............, " ..... "11' .... " ........... ' / ' +' '' - • .I ....... I_i: ,/ • i ...... it> ...... I. ,, _: : , I ...... , < ,, ; 7. Ul ....... _........ t ...... .'i-+ ...... +..... 4...........t .............. t-"t"i ......... !........ ""_ ...... 4.............. "_
' i. I: I::, '.:: ::.i : :.: i.:. :: : ii,i1:1::::i:: t:;:i::_'. !::: ;: . "it '
' _ ' 1 ' 1''' : " I .......... _, , !'1 '__ _' .... _,, " ',' ..... ' = ' " ? "T T T'rY "' T ........ rrTi" T -:'T" 7T:'T#T : ' : '.- ::"TiT't-" T r'!_. T!" T !'T'.'TI" T 'T: FTT ' TT'I' T 'T 'i-;' T i " T "'T" -- " V ;
' t '_.......... I' ......'_'tt .... '"""4 ..... _ "" "
..... , '1''; ........... I ............. I, " " '1 :, ...... ' ' I_ _ .i ...... i ...... t ....... i ............ I ......... : L n ....... '......... 1...... _ ............. r+"l ........ ' ............... '"ll ........ '-'- ............ '--' 1 .... " + ....
.... I / . : : , . , I .... I , :, ...... :t: , .I .... : , .... I ....... , .-..
: + -7-P::7 : :-:" _- ; -'_" :"-;:- _i-:-"-:-:- ]::-- '-- : _- : -" ; 4-'-:-7 ':--L------ ----:-+i _ ; -- i-A ;-7_ _
........ / ........... t .... / .... l ..... :_.1 ............... , • o
' 'l ...... i .... _ .............. ' + ....... t < !!_ ' '," ' +........
! .... t....... ...... !+ii .... :....... t' + l ......
! _ . ."-,_- " ...... -'_,--_ + - - : ......_.- , -... + .... . -- --, ....... ..! ., =_ ' .-- - -- , ----4.... - ..
_- i i ._ :i :"_ " _ : .: - ' .; t;! , _. . ,.:, ;_i , ,( : _i - J ' ; ...... ;: ; ' i 1_:7; :,T; :;.: ;.; . ; ' .7 ; ' . : :;:; ;:; . ',; '. ; 7:7 ' ,; ;::. i:;l _ ''I ; .... : ............... I ..... ill . . , . _i I . ; . , _i . , i _!:, ; ;' i _ 4
t .. ii , i _ _i_!!i:_. ttii_iiii ii_ _ _t ,: _ , _i: . _. -
ii!!: i!!: _:i:! ; ; , i | : _i:"_i ::: ii: ii::i :i ;:;:ti:! !:i: ii : :i i;"i _ii: - I i , , !i ' i I - I ' i i • i _ " _ '- =o • 0 0 0 II 0 0 • 0 0 It " 0 0 0 _" • • . . II o . • . . ill • • • i " - r 5 " ? i " - r E " ? l 6L-M'4R .... + ....... I ,i lii , 'll ' tl 179 _ / . 1 nf .__ , L ...................
I, ; ¸ o . ,4 ..... • ..... iii .... I " : . iI:i '., -- _ , .. _ , , _-- I* '.--'1 1 ' -- ! '_ .. L I " ' ' ........
:...... __4:': ' " - _ ....... _-.._ J ..... I ............. t .....J ........ ' ...... : ........ _:_ c 2 .......... I...... " .... o .... : ..... _ ,, _ ....... t ' " _ " ' "i ...... _ • . _ . . " I ' : 'i i .... i.. . : : . .-_ ......
" ':_:' [ k_ . I ! HHI:: L . : JI :... .....id "r -.._ , . l':"_ 'd • : -L _ .
• I _ : : " --- - --4 - .... _ ' " ' ' " i ' _ m ; • . i "_"_ . .::17:: ":;;I.;._ i ' _ ' 1 .. , ....... I . " _ ' _ .- .......... ,-_ '" ,' " --_ •' " -_I__ ..... .:!:I'. ¢ _"It ..... i : '_ - -:::: ; _ : . ; -J ........ ,I . < :. . ........ [ ..... _ , _ .
• , _ .... _ii:li,_. _ , . , -I- .
................ • -1 ....... , ' , _. ,- -_ ........ : .......................
...... t ......... : .... i .... ' " " : _: .......
........ J * ,i ', _4._ i - ] -_ ; F- I .... I - _ •_ I ......... i : " I ........ - _ ...I ..... , _ i ' ,' -- : _ • " ' , ' I ........... , .......... -- I • "t ; , !:_ ,...... ,_ ....:.... , :i_ _::-.-_ ' . "_ .
...... ............. _ '--r "" l _ ................. . .. I'- - -- ' - -_l!. 1: J...r ................ ', ....... , - -h ...... _' 1 1 ....... ...... .. r - : . ,: .. r-Tr- - I ' T_T T TT_I' • '- --//_ ,_ u _ o ' -- , . . ; .......... I .............. _ I • ; " - '-,t . _ ..... I' . . ' - 1" ', .... I% 1 ' , " '1:: ,. _ r ...
..... - r, .............. r .................. : ................ ,T !L"'----_" " ...........
.... -,,.. - 4 . . I ....... J . t 'r ..... $: : " "' .I , , , ., , . - ._" j , ..... , . _ , ; : :: .... ; . . ._ : ... _ .... : -- ,_ ...... _.C.I .... - , '--- ....... _ ............. _, ............. _-_ - -- - .--_---. , - : --t - -k : J- : ..... -r: ..... - "-
: _:i .: _ ! - i':'i .!:-! " _ " - ' _
• ....... i.................. _ ,; .... _,fl i: ....... i " :_: ' f!-i, ! (- .......... .:" : " r -:-:- ' ..... :__::: : -!: : ! ::- - " _ o
, / t _ _1-= -:! i' -
': : I ! . :i • ' : i : : :::-- ,, - , i .... : ....... ::" ::\ _ .... ' ' " ' i ' • . ,4:: , : L':: - I .... ....... : . ......... • ......
........ i .......... }" 1" . " : " T :" - T '--'-- :T - 1.." ' i " ..... " _ "l:. /
_: , ,. _:._ - _,_ _... _ . .._ , , . , _
' -- _ I ' _ ' t _
". . -: :'' "_ :::T i -- 5i - _ . I i , _l. : _l. : .!' : -: : !_l_ /
i !I i i I .... :. I .;.- _ . L . :I-: - - -.. - -i.-.-.- - | _:..: x / - _q.-- - i. . .. --, _- :.. -_-- ; - :l . -- - - _ - : .... l,--
i J : : _:_ : _ __! : i : ! _ ,' : _ ::J:: ' : : -L= . •
" _ -" ! , t l :. : i : : _': . a: " .- , _'.: .. : . I . . i • - l ¢ I . . . : ::: I
, _ . t ....... I . i ........ _....... 1'
L4 ....... ! ........ .... ...... I-
............ , .... I ' I I , .
. _ .... , . ... , t A . kil. , . ,,4: ] I:i_ ........ ..L.
" i i i I I I I I " " -- j ) -- -- I I I i l I I i • I I I I I O _I • o ? • I - 'I ' • ' " ' " ' I_ _ ,- I 1 4 10 2 o t I, L G L NA_L , PA G _ L '.
O 1 rP OO R q UAL I T _
...... - . : _. , . _. , _ L --..Z_ E I_j_ . _ _
i
k-till 1 95 !
• " .... _ i
_+ - _ ......
_I__:+; ........ +_ • ...... + ...... _+_ ..................... , ...... . .... + ,+ _ r ,, ......
|:
...................................... J
L ...... i
.... + .......................................
!
11 - I - 111
ORI G IN AL PAGE I_
........................... A
t ¢o 11"II 2 1 8
r
i
A
]
ll - l - I li3 'I !
?
I _ -II-II 25 1 ......... j i?
i +!
]
....... I....... i , - , , -,,4., + .,_ - ,. + ,iF_''"I " _ ' , , _ ,-i... - , ,. ,.. , -,. i ._,. . , , . , _., ............. . .... . ........ "!', .........
, ' I','" I , , _ l"l I T'i'l II i_ i l*lq 'I_ I"' i .... _ r , : : _I , ,_ ....... i ....... l,, i
.... "' : .....' ...... ' '"" ....... '.: ',: : : . i
o.
, _ I , , , _ , , _I.I i ..... _.,l.,l.i.l.i.l.,
"' " '" ' "" ...... .-',-q---... . ........ ..-4.--'-;a,-lq..::<:.:_.::.!-. l-s
:+", L
........... i ..i- .i..i ,. i i .i L .i ._.._ ...... i i ...... i. I q ' ;' , i _ .... ,. I ...... !i , . ,..,, i: : _I: L [ _:"Ir:H !..!!.:].I.,., ,,_I,_.,_,._.,I , _........ _,I..,: :: :: _::: : ' /: ",'41 :.: n, , , r_ ' ._ ..tl ! i..._ ...... ,........ , _ _............................ ' ...............
....,, _.,,,...,..,. :,.,.._ ,...._,.,. . , .... _.._..._:il..,. . .,.i. _ , _. , ..... ii..,. , .,..":1.,,.'._:11 : :,.:i.', :!tq; . :: / : _+'_.] : : lJ.; _N : i-! _..t. , .,.l . _.._.. _ ....... ; * ......................... , _ ......• ....... - , ........ _ ..... r_, .. "o iq.i..4, i..,.... ...... i. _ i._.; ;. , 4 't ..... i-. ;4_,.I f ,._._ " , _.'.''_,!, ' !
--_[.: '" t '_ " ' ! ' ;" t't '.:L!' i !"!' _'! I ! ' I ....._ t _ ..... _ _'" ' *" I • "_'_ ..... _ ....... _I__ ' "' d ' ." .... "] .... ' ! _ ,I':; " : /I b._..'
;_ ..+., . _., . ._ _. . , .,. + .,.. t., ._ _!t _.... , _ :__-_ . .; :_ . ,, • : _i_ :-.J i !. , _i.i._._ ii.,i.]i.4."
ii ,:1,"_ ,,..,.ij .....,._ _i i,_ ...... _'"'_ *' l , ",'i': _.i._.,..,,._ p _4. r'i', 4.!'"'i"' _'__',"1 ' _' ; -_.i","4!-i_". /,_ ,,_., ]ii:!_ ___, . : _._. ,_ . _ ; 1:.,. _:. . :ii .,.,._1, ....... ,., / , , •;!' } '_:_ !]!ill!!: """tt_'!" ....... ::. I_-!_::,:,.,_,';'_:_""_".:: :::"t_r_":_:::: : :: . L_r".'_ ...... ., "',,, _,,., L , '_: .;, ,; . I, ..... i.., ._t ' _ : "_ : t_ ,::*it _ . . . ::'::i: ': .t._ ::::1_. : :::: ::.::: /,_ ....... :i.;.' , .._.._._ L:.:.' , . :_ . ,. _...! . _ ..... i..;.i- ;.,..;.:.. _...., ,..;-..t,...;,.:_ :!!.1!-: : :!::" .................. _,. .. ..... + ,._ ............ ................
.,,, ...... ,..,...... _ ...... , ........ ,................ _ ...... _
• . : . l, • ,i :, ;.,._..: i.lii , .. . _ ...... _ ............ ; _., , . _, ......,- , ..... :, ................. .,, ..,. -- _ I
i : ";' " ......... :r °
:::! ! : . , ' I. 71:! t :: . i . ::::i _ :', :t.t._ :!:::l; . .,.; . ; s _,...... i..'.4.,_. , i ..... _ ,. _ ......... , ; _.___ ., _ + .i.i . _i._.!._i- . i_.i -i.ii . -:.mtl. r. ' ._ : '."_ .... :_....._' : " .
--4--, .--_- - .- , ..... _, .... _ ..... -,-.... _. , ,r-
' ' : ' 1" '' _* ,_ .... i ' . !f"t ! t : i.i! _-"_ : i!; , "I ! i-i : _t•i • ! : '!'i i'""}i_,_t:'i '!"!r'"l: :" :__ __ , !
:::Ltt:t . '::i:: .::: .; !,_:: ::::: :;:;;: ,,:.,.,.k:::: ;::::. ::.; - _, :: : , . i.:_1:i:_:::t: . _:_: . _.:_ _:t:_:;: _ ..... :t . .. ;..,_, ..... , ,,. . , ._,. . ,,._ , . . , .., ., . 'v.. . ._, ........ t , _ . .
..... I '_'_ _ '._._ , I ._,.. , ._ ',,.". . .!.H., . . .i .i.i "_ ' t i. _ . _: , . , 4 _. _'_:,._ _'!i ! 't 'i'i'_ i4 i ; .1_ , : :, / :_ i , I ..... -- /° /
" _l:_tl t t _ t , _."i
;.; , . ; .., ; _ , +... .;. 4.. ; . .;i. ,.i_..:: ;.,4,. m ; i i.+,. ,..,., _"._q _.i.: i.;- - _ ........... ,.. .i.. ,..,..... ..i..i ......... -- O I , . ., . ,._ l . ,.., . ._..i._ i.I _...;,.'_,._._.. . i_,¢ . ;.._. . i. , 4;.,._t.._._..ili_i.i I,i._,_..,.._._. --/. _ , .
__:! _ti. : b:.l ...... ,, . ., 1..... ; : ,,I.._i *_.]._.I._,.!...i.:._ ,*_ ' i' . _ : ']i; :_ 1 ,, a ' ! ' ; ' " r'_"i"! i ' ! "'i _" '!"_',l ....i" .... ,,., ........ ,-' ._.., _..,.,... ._* ,- ,-, _._ _ _':- _--_'-'---':l' d :' I _i¢:?_¢Ht:!:_: :::?-!::!.!t::>'_i . ,:!: !: !.:: _,i. . _: _. ,:t:' .. _4-!: ; _. ; t_'-,.i li:!!it. . i_., gL_. • t !' _ ! i ' ! : ' t' t ' ! _ _ ' " "!"t ' ¢ ] ! ' "_'! " f _._. !. . _ . i * !'t _" * _ •!" _ ll _ ,,., ...... !_ .......... _.4 .f,., i . .., '....... _";"" I_"_ ' ; l,'i_ ;..i4.+ _,.. I _. . ,.i i. ,:i _,_.;..;.i;.. ' _ '_ "'" _-! *..... '.... ,, - *-_-,., , ., f: , :_. , . _, 1_,.i:!i::!t:,,.,. i., _:!il_. ,., !!:i:., I,_,el _
tt: _#q]
I . : . ,.! I._1 ..... , , . .;.i , _ . _.,, .... i.'
• • .... _ • ' . -:*.' e . _ 4 .._.. _ * ': ]4 . _., _ - _;l , _..i_!:i , !t_.i.i L _i ,.. , . ] _i, . -t - ,; .; . _._,, _ , . _, . i . , .! , .i • _ i1 ., _ . ;; ........ i . _ . 4,. . i. = , . _ _-i ,. _ _ _..i , _ .......
!._., , |._i..!.-: ..... i ' Jl, . , 't !'_'t ' ]_'i, ' _ . ._.,_ 11, , - ! ....... ]'""_ .... _| ,i _ _!.",.!I_. !_ '" "'"'_ ' "I !_"__ " _.i , , 4, , i. . .i_ .'' * . i' _.. * * .. .i. : i. , _ 0
• " " "" "- . , _ S. S. i s . s. I
i¢ ,,ll-i ?
; 271 _ r _ _ L" +o*_ " _ " 2_T_. _,,__ TM L_, : :....
r_ ........... " ........ ++++" ............ * ......... • - _............. _!
li,+ ¸
+ 1
.... +- w I , -11 4 1
2aS O R IGL N A L P A GE 1 5
O F POOR Q U AL IT Y - _
_- - - _
) L .
"., , ++ L ....
I d l, - tll-t 3O9 li - tl-liii
3 1 o O I _ IGINAL PA GE L5
O le POORQUA I ,|TY ,
L ..................................................... ............................ A
312 " RUN = 23 POINT= 20 20 -
-
_ o
GQQ =20 l--- _ . _ i ' ' I I I I | i lliilii
o i
-1 80 _ 60 1 6 10 20 FREQUENCY . Hz G AIN MARGIN. dB = 11.2 Fl sure 1 9.- Bode p lo t o f measured hub- m om e n t feedback co nt rol s t ab l l lt y; fi xed- wi ng m ode. P i tch l oop stab ili ty measuremen t r i ch ro ll loop open.
RUN -- 23 POINT ,, 38:1
' ° I
O iii -20 -1_
i °°
1 5 10 20 FREQUENCY, Hz GAIN MARGIN, dB = 19.5 Flgur e 20.- Bode plot o f measured hub-moment f eedback control stabili t y; fixed-w i ng mode. Roll loop stab i l i ty me asureme n t v it h p i tch loop open.
i+ + J • i RUN = 23 POINT = 38:2 ....
----'- --- " " * I I I I i llllllli
f o
-36O 1 5 10 20 FREQUENCY , Hz GAIN MARGIN, dB = 10.0 ¥1 sure 21.- Bode plot of m eas u red hub- _m e nt feedback c o n trol stab i l l ty; f l xed- wi n g m ode. Pit ch loop s t ab i l it y m easure m e nt wit h roli loop open.
i
RUN - 23 POINT ,, 38:3 l 1 5 10 20 FREQUENCY , Hz GAI N MARGIN, dO - 9.8 Flsure 22.- Bod e p lot of me as ured hub-moment f eedback control s t a b i l it y; ff£ xed-vin 8 m ode. ? itch loop stability m aeur l men t _ r l th roll loop closed.
T;
l
i
!
,) 33 0 i i RUN " 26 POINT" 9 -2 0 - 180 - 360 1 5 10 20 FREQUENCY , Hz _ GAIN MARGIN, dB = 5.7 Fi g u re 23.- B ode p l ot o f meas u red h ub - m o m ent feedback co n trol sta bi l i ty; ro ta ry- wi n g m ode. P itc h l oop stab ili ty me asur em ent wi th roll loop open.
RUN., 28 POINT " 10
OQQ
-11111 1 8 10 20 FREQUENCY , Hz G AIN MARGIN , dB - 13.3 Fi sure 24.- Bode plot o 5 m ea s ured hub- m oaent _e edbeck control st ab i l i ty; rot a ry- wi n g soda. R oll loop s tab i l i ty aea s ur a mnt with p i tch loop open.
!
) !
J L RUN " 25 POINT " 11 2O
, |
.. o°
1 5 10 2O FREQUENCY, Hz GAIN MARGIN, dB - 4.4 Fisure 25.- Bode ploc of m easured hub-moment feedback con t rol s t ab i l i ty; ro ta ry-w l n& mode. Pitch loop s ta b i l l ty me asur e men t with roll loop cl o sed.
r q RUN - 27 POINT - 16 ,!
i ; 20
_ 0 _ i _ 0
E
1 § 10 20 I FREQUENCY. Hz GAIN MARGIN , dB" 11 , 1 i F t B ur e 26.- Bode plo t o f measured hub-m n t feedback con t rol sta bili t y; r o ta ry-vln s mode , Pitch loop sta bil it y m ea s uremen t vl t h roll loop open.
, 8
i
RUN 27 20 _ " I " POINT " 17 _ 0 , <
I 5 10 20 FREOUENCY, Hz GAIN MARGIN, dB - 13.0 Fi gure 27.- Bode p l o t of meas u red hub-mome nt feedback co nt ro l s t ab ilit y; ro t ary- win g mode. Roll loop st abil it y m easure m en t wit h p it ch loop open.
L, i RUN = 27 POINT ,, 18
_ o
I_ QQ
_
o
1 5 10 2o
r FREQUENCY , Hz I GAIN MARGIN, dB ,, 11.5 Fi gure 28.- Bode plo t of measured hub-u _m n t feedback con t rol s t ab i li t y; ro t ary-v l ng mode. Pi t ch loop s t ab i ll t y m easure m en t w it h p it ch lo o p closed.
33 6 RUN = 27 POINT = 19 "15
o
< X -20 -18 0 -360 " 1 5 10 20 FREQUENCY, Hz GAIN MARGIN, dB - 11.7 Figure 29.- Bode plot of measured hub-moment feedback control stab i llty; ro t ary- wlng m ode. Roll loop s t ab i li t y m easuremen t w i t h p i tch loop closed.
3 37 R UN., 34 POINT " 14 2O
|
?
- 180 a_ 1 6 10 20 FRf QUENCY , Hz : _
r !
GAIN MARGIN, dB = 17.6 ', r F i sur e 30.- Bode plot of m asur e d hub- m o m en t feedback control stab i l it y; rotary- wl ns mode. Itoll loo p stab L l l ty .mesurm R nt with pitch loop open.
i !
!
k : i 33 8 RUN = 34 P O INT = 15
o
°20 _ 0 _ -180 - 36 0 1 5 10 20 _ FREQUENCY , Hz GAIN MARGIN, dB = 11.7 Fig ur e 31.- Bode plot of measured hub-. _ nent f eedback control stab i l i ty; ro t ary- wl nS m ode. P i tch loop stab i llty measuremen t with roll loop open.
RUN-34 POINT=1 8
o
|
1 § 10 20 1 FREQUENCY, HI : F GAIN MARGIN , dB - 13.8 i !
b i_ i F i gure 32.- B ode plo t o f m easu r ed hub-mo m ent f eedback co. t t ol s t ab i l it y; r o t a r y- w i n g m ode. Roll loop stabil it y mea s u r emen t v it h p it ch loop closed.
3 4 O i __ j J RUN = 34 POINT = 17 2O oo '15 m
_ " o
o o o_o_l_._w._ _ _
-2(] -_ 0 _ 1 5 10 20 FREQUENCY , Hz GAIN MARGIN , dB = 11.2 Fig ur e 33 .- _J od e p l ot of me asur e d hub -m o m ent f eedback contro l st a b ilit y; rotary- wl n 8 m ode. P itch l oop stab ili ty me asure m en t wit h r o ll l oop c l osed.
RUN - 3 6 POINT - 3 2O -180 1 5 10 20 FREQUENCY , H z GAIN MARGIN, dB - 10.5 i_ F igu r e 3 4 . - Bode plot of m easured hu b- m o m ent feedback control stab i l i ty; rot a ry- wl n s B ode. lto11 loop stabillty me asure m ent vlth pitch loop open .
J RUN" 3E POIN1 "4 i -20
°Iooo.... _ ---
-3601 5 10 20 FREO UENC Y, Hz GAIN MARGIN , dB " 8.0 Fi gure 3 5 . - Bode plot of measured hub- m o m en t f e ed b ack control stab i l i ty; ro t ary- w ing mode. p it ch loop s t ab i l it_ m easu r e me n t wit h ro l l loop open.
34 3 RUN - 36 P O INT ,, 6 -20 , i i i i i i iiill,
oF
1 5 10 20 FREQUENCY , Hz GAIN MARGIN . dB " 9.6 F i gure 36.- Bode plot of m easu r ed hub- m o a ent feedback control stab i l i ty; rotary-vtn8 m ode. Roll loop stab i li t y measurement wi th pitch loop closed.
344 i
i
t , ] i RUN ,' 35 POINT = 6 0 m E3E ) - 20 _ 0 -180 -360 1 5 10 20 FREQUENCY, Hz GAIN MARGIN, dB = 9.3 Figure 37.- Bode plot of measured hub-m o m en t feedback con t rol s t ab i li t y; r ota ry - w i n g mode. P it ch loop s t ab ilit y m easure m en t w it h ro l l loop c l osed .
_d
P
RUN= 3 6 POINT- 4 QQQ
, _ _
0 Q 1 5 10 20 FREQUENCY , Hz GAIN MARGIN , dB= 11.1 i F i sure 3 8.- Bode plot of measured hub-moment feedback con t rol s t ab i l it y; ro ta r y - w ins mode. Roll loop st a bil it y measu r eme nt wi th pitch l o op open.
3 h 6 RUN = 36 P O INT = 5
" o 0130 Q
' ° I
-2 0 ! "_'_ I i . i* ,l,**,*l - 1 _ Q _
o I
1 § 10 20 FREQUENCY , Hz GAIN MARGIN , dB= 8.0
r
b L ' , Fi gure 39.- Bode plot of measured hub-moment feedback control s t ab i l l ty; ro t ary- wl n s m ode. P it ch loop s t ab i l lt y m easure m en t wit h roll loop closed.
34 7 _ a l RUN - 38 P O INT - 8 G GB G - 20 - 1 _ ® ® " _ 0 I I l I Illlllll 1 5 10 20 FREQUENCY , Hz GAIN MARGIN , dB = 9.9 F i g u re 4 0.- Bode plot of m easured hub-mo m ent feedback control st a b i l it y; i ro ta ry-w l ng m ode. Roll loop st n b l l lt y m e a s u re m en t wi th pi tch loop op e n .
{ :
i
t ( 3 h 8 r RUN " 38 POINT - 9 _ _oo___. o ..............
-2 0 O "
_ -- ° °_ _ "
-360 i , , ,,,,,,,,,,, 5 10 20 r FREQUENCY, Hz GAIN MARGIN , dB = 11.0 Fi g u r e 4 1.- Bode pl ot of m e a s u red hub- m o m e n t f eedbac k control stab il ity; r o t ary-win 8 mo de . P i tc h Icop st abili t y m ea sur e m ent wi th r oll loop op en .
3 4 9 l I i RUN = 38 POINT = 10
o
-20 1 5 10 20 [ FREQUENCY , Hz ! , GAIN MARGIN , dB - 19.3 Fi gure 4 2.- Bode p l ot of measur e d hub-mom e nt fe e dback contro l st a b ili ty; rot a ry-wlng m ode. Pitch loop stab i l l ty me aaurtq m nt w lth pitch loop open.
35O RUN-39 POINT-4 m "o
_ " o
< :_ Q Brn _ 20 i - 180 - 360 1 5 10 20 FREQUE N CY , Hz GAI N MARGIN , dB = 18 . 0
r
F i gur e 4 3.- Bode p l o t of measured hub-momen t feedback con t ro l s t ab i l it y; _ f l xed- wi n 8 m ode. R oll loop s t abll it y m easure m en t v lt h p it ch loop open. j 35 1 RUN - 39 POINT - 5 1 5 10 20 FREQUENCY , Hz GAIN MAR G IN, dB - 1 5.3 Fig ure 44 .- Bode plo t of measured hub-momen t feedback co nt rol s t ab i l it y; fl xed- wl ng m ode. Ro ll l oop stabi li ty m easureme nt wi th ro ll loo p o p e n . !
+: 3 5 2
RUN - 3 9 P O, N T- 7
o
I E
20 _
- 180 -360 I 5 10 20 FREQUENCY, Hz GAIN MARGIN, dB " 11.1 1 Figure 4 5.- Bode plot of m e a sured hub-mo m e n t feedb a ck control st a b i lity; : _ f i xe d -v lngm ode. Pi t ch loop stab i li t y m eas u re m ent wit h roll l o op open.
353 ' i
t
! RUN - " 39 POINT ,, 8 : ¢_d 0 .....
Q_ ] Q_, . -- . . . . , , , ,, ,,,,,,,i
-2 0 ' .
, _ -180 1 5 10 20 FREQUENCY, Hz GAIN MARGIN , dB = 12.8 Fi g u re 46.- Bode plot o f measured hub-mome n t feedback contr o l stabll i ty; fi xed-wl n g mode. Roll loop s t ab i l l ty m easure m e nt v l th p i tch loop open.
_ RUN = 39 POINT = 9
i
20 r- no < 0
=E r n BB_
-20 , _ ,. l . _ I '* ,,i,,,,,ii • , • • • • , ill| -360 I _ L 1 5 10 20 FREQUENCY, Hz GAIN MARGIN, dB = 11 , 3 Fi g u re 4 7.- Bo de p l o t of m e a sured h u b- m o me n t feed b ack co nt ro l s t a bilit y; fi xed- w ln g m ode . Ro ll l oop s t ab ilit y m easure m en t wit h p it ch I oop c l osed.
RUN " 39 POINT - 11 l 2O
= l
t, _ , _l • II . I ,i • I. I. l.]. ] _ | I[, | | II I II l U lII[t _
o F
-180 ' ?
1 5 10 20 FREOUENCY, Hz GAIN MARGIN, dB = 21.1 Fi s u re 4 8 . - Bo d _ p l o t of measured hu b -mo m e nt f eed b ack c ont ro l s tabilit y; f txed-v l ng mode. Pi t ch loop sta b i l ity mea s ure m en t vt t h r oll loop open.
i ;
, _
J
!
3 5 _
i
t i Figure 4 9.- Bode plo t of measured hub-momen t feedback control s t ab i l it y; fixed- wi n g Node. Roll loop s t abili t y measuremen t w i t h p it ch loop open.
RUN = 39 POINT - 14 0 .'' -2 _I t _ " _" ' _ ] _ l ' '' _ ' ''' ''';''''' ''
- 1 80 l Q
-360 _ !
1 6 10 20 FREQUENCY, Hz GAIN MARGIN , dB- 14.6 J F i sure 50.- Bode plo t o f measured h u b- m ome nt f e edback con tr ol s t ab i l it y; f i xed-w i ng mode. P it c h l oop ° t ab ilit y m e a s ,ar ement wit h ro ll l oop open. _i: , 358 RUN=39 POINT=15 20 - _ 0 _ ' ' ' " f _ l _ [ _ m , , , l_i i I I I I llllil - 20 - i.!.,.I: ,.iol i i ,, ,i l lll,'llilii, -180 O -360 ' i ,, i i - _ i , , J i il ,,J i JJJ 1 § 10 20 FREQUEN C Y . Hz GAIN MARGIN , dB= 17.4 Fig ure 51.- Bode plo t of m easur e d hub-momen t feedback con t rol s t abi l i t y; f i xed- wi ng mode . R o ll l oop s t ab ilit y m easu r e m en t wit h pitch l oop open.
3 59 I RUN = 39 POINT = 21
d o
< :Z In -20 O Q_ .H: l . _J ; I ,,,;,,,,;,,,,',, " -- * | ' I ' ' ' ' ' ' " ' -180 ' 0 0 0 Q _ -360 I 5 10 20 FREQUENCY, Hz GAI N MARGIN , dB = 15.8 Fi gure 5 2 . - Bode p l o t o f me as ured h u b-mome nt feedback con t ro l s t ab ilit y; f i xed- wi ng m ode. Ro l l loop st ab ilit y r a easure m en t wit h p it ch l oop open.
36O
I
RUN - 40 POINT - 1 8
' !
i °
• _ !oQQ
-20 |_ , i i iiliilllll o f ', f -360 i .
1 5 10 20 i FREQUENCY , Hz .i GAIN MARGIN, dE ,, 14.8 ii t_ F i g u re 53 .- B ode p lot o f m e a s u red h u b -m o m en t feedb a ck co n tro l s ta b ility ; i_ r o ta ry- w i ng m ode. Pi t ch l oo p st a bility m e a . q ure ment w i t h roll loop ope n . i !
r
!'
RUN-40 POINT-17
_ o
-2 0
-360
1 5 10 20 FREQUENCY, Hz , GAIN MARGIN, dB = 11 , 2 Fi gure 54 .- Bode p l ot of measured hu b-m ome n t f eedback cont r o l stab l l it y; ) rotary-w l n S m ode. Roll loop stab i l l ty m easure m ent wi th pitch loop open.
:)62 i _qINlUN n _m_m_ " - L ........
RUN ,, 40 POINT = 18 - 20 - 180 - 360 _ 1 5 10 20 FREQUENCY, Hz GAIN MARGIN, dB ,, 7.0 Figure 55. - B ode plot of m e a s u red h u b -m o m ent f eedb a ck co ntr o l s ta b ili ty; rota ry- wi ng m ode. P it ch loo p s ta b ilit y m e a sure m en twit h r o l l l oop o pen.
RUN = 40 POINT " 19 m 20 I -20 _- 180 -360 _ 1 5 10 20 i FREQUENCY, Hz _ .
GAIN MARGIN, dB = 8.4 i i F i gure 56 .- Bode plot of m e a sured hub- m omen t feedback con t rol sta b ilit y; ro ta ry-w i ng m ode. P i tch loop st a b i l it y m e a surement wi th roll loop closed.
i i
3 6 4 . ] RUN=40 POINT=22 _ 0 "
_ 121
-20 _
I i - l eo
- 36 0 1 5 10 20 FREQUENCY, Hz GAIN MARGIN. dB = 20.3 Flgu ze 5 7.- B ode plo t o f m e a s u red h ub - m o m ent f eedback co n tro l sC abill t y ; r ot ary- wingmod e. Ro ll l oo p s tabilit y m e a s ur emen twith pit ch l oo p o p e n . i ! 3 6 5 i 4 1 RUN - 46 POINT = 5
=E OQQ
- 18 0 - 360 I 5 10 20 FREQUENCY , Hz GAIN MARGIN, dB - 13.6 : Fig ure 58.- Bode plot o f measured hub- m o ment feedback control s t ab11 1 ty; rotary- v ln g m ode. Roli loo p stabillty m ea s urement v lth p i tch loop open.
36 G : i : i - !
J RUN = 46 POINT = 7 "O _ 121QQQ -2 0 i "___0, , ,,, ,,,,,,,,
°F
i -1 80 _ i I I i _ i I I l I I i illllll -3 6 0 _" 1 5 10 20 FREQUENCY, Hz J GAIN MARGIN, dB = 11.1 Fig ure 59. - Bode plot of measured hub-momen t feedback control stab i li t y; ro t ary- wi ns m ode. Pi t ch loop s t abili t y measuremen t w i t h roll loop open.
t_
I
! , o ,., _ o,, T .,
i _ 2 ° I
-20 i , , I iii,lllli
°
-360 (2)i , i i i l" ' " ii' 1 5 10 20 FREQUENCY, Hz I GAIN MARGIN dB,= 11.6 Fi g u re 60 .- Bode p l o t o f mea sur ed h u b - mome nt feedback co nt ro l s t ab ilit y; ro t a r y- win S m ode. P it ch lo op s t ab i l lt y m ea s ure m en t w it h roll loop c lo sed.
RUN=46 POINT=11 " 0 E3Brn m
= . _
o F
1 5 10 20 FREQUENCY, Hz GAIN MARGIN , dB = 7.4 Figu re 6 1.- Bod e pl ot o f m e a s u red hu b - m om e nt feed ba c k c ont r ol s tabilit y; " r ot ar y- w ing mod e . P it c h loo p st a bilit y m ea su re ment with r oll loop op e n.
369 .
'i